This invention relates to a mechanism for disengaging the wing of a window, a door or the like, a wing of which is pulled out and blocked into a stable position parallel to a stationary frame for the purpose of being slid horizontally and sideways. This disengagement is provided in part by upper and lower swing out arms, each of which is pivotally mounted at one end to the lower transverse bar of the wing and at the other end to a traveling carriage on the stationary frame. A mechanism for releasably blocking at least one of the swing out arms in the position where the wing is located in its stable position parallel to the frame comprises a control arm operatively connected to the swing out arm in the region of the traveling carriage. This control arm can be brought into and out of operative connection by means of a control lug associated with a thrust bearing located on the stationary frame near the limit of the motion of the wing when it is slid closed. This control arm is supported on the traveling carriage in a horizontal plane, and its movement is limited to swiveling in that plane. The control arm functions as a two-armed lever, one of the arms being free and carrying a locking link which extends in the same direction as the wing when the wing is slid closed.
A mechanism of this kind is shown in DE-GM No. 84 35 367.
This control arm, which is able to swivel in a very limited manner and is mounted on the traveling carriage, acts through a second lever arm directed away at an obtuse angle from that lever arm which is carrying the locking link. The arm acts as a supporting link, along with the adjacent swing out arm, when the mechanism is blocked into the parallel stable position. By this assemblage, the forces which act in a closing sense on the wing when it is in the stable parallel position are positively but unsymmetrically introduced onto the traveling carriage and supported by the guiding runners. This support is through the pivot bearing of the swing out arm as well as through the swivel bearing of the control arm which is spaced from it.
Such a swing out arm, however, is freely pivotally mounted at the lower transverse bar of the wing and therefore the action of forces transmitted to the traveling carriage are introduced unsymetrically to its runners and into the stationary guide rail of the frame side. The result can be not only undesirable deformations of the guide rail but also it is possible that the runners of the traveling carriages may run up at the rounded off profile of the guide web of the guide rail and thus get out of guide engagement with it.
The same difficulties are also seen in a mechanism as shown in DE-OS No. 32 34 677. There, an additional arm is connected in a swivelable manner to the swingout arm at one end and engages at the other end by means of a pinion in a guide slot on the traveling carriage. This guide slot is provided with a stop uptake for the pinion of the additional arm when the wing is in the parallel stable position.
In this case the stop uptake for the pinion of the additional arm is spaced a considerable distance from the pivot bearing of the swing out arm which is also on the traveling carriage. Since the guide slot is situated in a spiked continuation of the traveling carriage which projects in the direction of wing when it is slid closed, the deficiencies of the mechanism shown in DE-GM No. 84 35 367 appear here in a still higher degree.
These deficiencies are not apparent in the mechanism shown in U.S. Pat. No. 2,741,807 because in that case, the control arm which acts as a supporting lever is able to introduce the action of forces exerted upon the parallel stopped wing transverse to its plane. This is because it is pivotally mounted in alignment with the swing out arm directly into the stationary frame, thereby bypassing the travelling carriage. This is only possible however, when the control arm consistently interacts over the whole length of the horizontal slide path of the wing with a rail-like thrust bearing which is mounted on the frame or otherwise stationarily mounted. By this means, the parallel stop position of the swingout arms can be maintained by the control arm throughout any possible sliding position.
In the fitting according to the French patent No. 1,551,381, the control arm which is pivoted at the traveling carriage and acts as a supporting lever, interacts constantly with the guide rail which carries the traveling carriage until the wing has slid to the end position of its closed configuration. It is only at this point that the control lug and the control arm with the swingout arm are freed. Subsequently, the wing can be moved, by means of the swing out arms, into its closed position at the stationary frame.
It is a characteristic disadvantage of all the above discussed known mechanisms that the pivotal connection of the swingout arm in its interaction with the releasable blocking device continues to be maintained when it is in its parallel stable position. Because of this, angular displacements of the swingout arm relative to the wing when in the parallel stable position cannot be effectively eliminated.
It is therefore, a primary object of the present invention to provide a disengaging device of the above mentioned type in which the swingout arm, interacting with the blocking device, is positively braced or blocked against the wing when in its swivel position corresponding to the parallel stable position; while at the same time, the functioning of the releasable blocking device and the interaction of its control lug with the thrust bearing situated at the stationary frame is not impaired during the end movement of the wing as it is slid closed.
Other objects of the invention will become apparent as the details of an embodiment are disclosed.